Search results for "Agonism"

Antagonism of the endophytic Bacillus subtilis strain AG1 to fungal pathogens that cause tracheomycotic deterioration of wine wood

2008

Grapevine trunk diseases can determine considerable losses in the worldwide wine industry. Symptoms of wood diseases are dead spurs, arms, cordons and same times vine death, due to cankers in the vascular tissue (Pascoe, 2000). Recent research has also showed a recrudescence either of escadisease or decay by Verticilliumdahliae and the occurrence of new wood alterations (Botryosphaeriarhodina; Mugnai et al., 1999; Wood et al., 2005; Bonfiglioliet al., 2007). Last investigations, carried out in Sicilian vineyards on fungi associated with xilematic“esca”symptoms, revealed the occurrence of genus Bacillusin wood tissues. A spore-producer Gram-positive bacterial isolate, named AG1, was identifi…

2020

As many, if not most, ligands at G protein-coupled receptor antagonists are inverse agonists, we systematically reviewed inverse agonism at the nine adrenoceptor subtypes. Except for β3-adrenoceptors, inverse agonism has been reported for each of the adrenoceptor subtypes, most often for β2-adrenoceptors, including endogenously expressed receptors in human tissues. As with other receptors, the detection and degree of inverse agonism depend on the cells and tissues under investigation, i.e., they are greatest when the model has a high intrinsic tone/constitutive activity for the response being studied. Accordingly, they may differ between parts of a tissue, for instance, atria vs. ventricles…

Lipopolysaccharides-mediated increase in glucose-stimulated insulin secretion: involvement of the GLP-1 pathway.

2013

Lipopolysaccharides (LPS) of the cell wall of gram–negative bacteria trigger inflammation, which is associated with marked changes in glucose metabolism. Hyperglycemia is frequently observed during bacterial infection and it is a marker of a poor clinical outcome in critically ill patients. The aim of the current study was to investigate the effect of an acute injection or continuous infusion of LPS on experimentally induced hyperglycemia in wild-type and genetically engineered mice. The acute injection of a single dose of LPS produced an increase in glucose disposal and glucose-stimulated insulin secretion (GSIS). Continuous infusion of LPS through mini-osmotic pumps was also associated wi…

Cachexia: a therapeutic approach beyond cytokine antagonism

2002

Cachexia is seen in a number of chronic diseases, and it is always associated with a poor prognosis. Irrespective of etiology, the development of cachexia appears to share a common pathophysiological pathway. This includes induction of proteasome-dependent myofibril-degradation, which is thought to be secondary to stimulation by enhanced levels of pro-inflammatory cytokines. Elevation of tumor necrosis factor-alpha (TNFalpha) and other plasma cytokines has been demonstrated in many conditions associated with cachexia. Despite improved pathophysiological understanding, a specific treatment for cachexia has not yet been established. Whilst direct TNFalpha antagonism has therapeutic appeal, th…

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2007

Acetaldehyde as a drug of abuse: insight into AM281 administration on operant-conflict paradigm in rats

2013

Increasing evidence focuses on acetaldehyde (ACD) as the mediator of the rewarding and motivational properties of ethanol. Indeed, ACD stimulates dopamine release in the nucleus accumbens and it is self-administered under different conditions. Besides the dopaminergic transmission, the endocannabinoid system has been reported to play an important role in ethanol central effects, modulating primary alcohol rewarding effect, drug-seeking and relapse behaviour. Drug motivational properties are highlighted in operant paradigms which include response-contingent punishment, a behavioural equivalent of compulsive drug use despite adverse consequences. The aim of this study was thus to characterize…

Toxicity evaluation of individual and mixed enniatins using an in vitro method with CHO-K1 cells

2013

Enniatins (ENs) A, A1, B and B1 are produced by Fusarium species. They are known as emerging fusario- toxins, and can cause outbreaks in both humans and animals. ENs elicits a wide range of different biolog- ical properties and toxicological effects, and their co-occurrence may enhance the extent of these hazards. As the potential toxins reach in vitro cells in the same way as they would in vivo, cytotoxicity was studied with CHO-K1, which is considered one of the most sensitive cell lines for preliminary screen- ing of cytotoxicity studies. In this study, individual cytotoxic effects of ENs were evaluated by MTT assay after exposing ENs to CHO-K1 cells for 24, 48, and 72 h. The IC50 values…

Selectivity of pharmacological tools: implications for use in cell physiology. A Review in the Theme: Cell Signaling: Proteins, Pathways and Mechanis…

2014

Pharmacological inhibitors are frequently used to identify the receptors, receptor subtypes, and associated signaling pathways involved in physiological cell responses. Based on the effects of such inhibitors conclusions are drawn about the involvement of their assumed target or lack thereof. While such inhibitors can be useful tools for a better physiological understanding, their uncritical use can lead to incorrect conclusions. This article reviews the concept of inhibitor selectivity and its implication for cell physiology. Specifically, we discuss the implications of using inhibitor vs. activator approaches, issues of direct vs. indirect pathway modulation, implications of inverse agoni…

A systematic review of inverse agonism at adrenoceptor subtypes

2020

As many, if not most, ligands at G protein-coupled receptor antagonists are inverse agonists, we systematically reviewed inverse agonism at the nine adrenoceptor subtypes. Except for β3-adrenoceptors, inverse agonism has been reported for each of the adrenoceptor subtypes, most often for β2-adrenoceptors, including endogenously expressed receptors in human tissues. As with other receptors, the detection and degree of inverse agonism depend on the cells and tissues under investigation, i.e., they are greatest when the model has a high intrinsic tone/constitutive activity for the response being studied. Accordingly, they may differ between parts of a tissue, for instance, atria vs. ventricles…

Evaluation and synthesis of 7-arylhydroxymethyltriazolopyridines as potential cardiovascular agents

2002

7-Arylhydroxymethyltriazolopyridines 3a-c and 4a-d were synthesized by regioselective lithiation of [1,2,3]triazolo[1,5-a]pyridines 1 and 2 and subsequent trapping of the 7-lithioderivatives formed using aryl aldehydes as electrophiles. The structural relationship between compounds 3a-c and 4a-d and arylethanolamines suggested their consideration as potential cardiovascular agents. A preliminary evaluation as vascular smooth muscle relaxants was carried out. These compounds did not act as α1-adrenoceptor antagonists and were unable to block calcium entry through voltage-dependent calcium channels. Abarca Gonzalez, Belen, Belen.Abarca@uv.es ; Ballesteros Campos, Rafael, Rafael.Ballesteros@uv…